Sewing machine



Oct. l1, 1960 J. c. MCGAHEE 2,955,552

SEWING MACHINE Filed May e, 195e gb FIG. 4

l i fla 26 22e-Eil (D FIG. 5

INVENTOR.

BYJOHN C. Mc GAHEE United States Patent O SEWING MACHINE John C. McGahee, Thomaston, Ga., assignor to The B. F. Goodrich Company, New York, NX., a corporation of New York Filed May s, 195s, ser. No. 733,917 1o claims. (ci. i12-2) This invention relates to sewing machines and, more particularly, to improvements in the throat plate and presser foot of such a machine.

It is frequently desirable to unite or splice two cords in a manner which provides a smooth connection thereof with a minimum cross section. Various knots have been devised for this purpose but all suffer the common dicultyof an abrupt change in cross section at the knot and the transverse section of the latter is excessive so that it is frequently diiiicult to achieve smooth running of the united cord portions through guiding and tensioning devices.4 Moreover, the presence of a knot isfrequently undesirable in material in which the cord is incorporated. Splicing the cords by stitching them together obviates these difficulties but unfortunately conventional sewing machines do not have mechanisms for easily and accurately effecting such an operation.

The principal object of this invention is, therefore, to

provide improvements in a sewing machine such that the latter is capable of rapidly and accurately-uniting two cords in parallel relationship by a stitching operation so that the transverse dimension of the region of union does not exceed the combined diameters of the cords. A more specific object of the invention is to provide improvements in the throat plate and presser foot of a sewing machine, that is capable of engaging material alternately at two laterally spaced locations, such that two cords are held in parallel contiguous relationship while being fed through the stitching mechanism of the machine whereby the cords are stitched together.

A still more specific object of the invention is to prorvide improvements in a sewing machine characterized by a groove on the lower surface of the presser foot which groove is adapted to receive two cards to be spliced in `parallel contiguous relationship, a means carried by the throat plate of the machine to retain the cords in position in said groove during a sewing operation, and means for retaining the presser foot and throat plate in predetermined vertical alignment in all positions of the presser foot.

Further objects and advantages of the invention will be apparent to those skilled in the art to which the invention pertains from the following description of a preferred embodiment described with reference to the accompanying drawing, forming a part of this application, in which: "Fig 1 is a somewhat schematic perspective view of a sewing machine incorporating the novel features of the invention;

Fig. 2 is an enlarged fragmentary front elevational View of the novel throat plate and presser foot separated from the other parts of the sewing machine with the presser foot shown in its position of maximum separation from the throat plate;

Fig. 3 is an enlarged top view of the throat plate shown 2,955,552 Patented Oct. 11, 1960 ICC Fig.y 5 is an enlarged elevational view of two cords united by sewing in accordance with this invention.

. The invention is illustrated as incorporated in a sewing machine of the type adapted to perform a stitching operation alternately at two laterally spaced locations. Machines of this type are well known and are commonly referred to as adapted to perform overseaming and zigzag operations. A machine 10 of this type is illustrated in Fig. 1 as comprising a head 11 having an arm portion 12 provided with a needle bar 13 and a presser bar 14. The needle bar carries a needle 15 to which thread is suppliedrfrom a spool 16 through the usual feeding, guiding and tensioning means. The needle bar is reciprocated and laterally shifted so that the needle engages the material to be sewn at two laterally spaced locations thus providing a zigzag or oversearning stitch which is locked by thread supplied from beneath the base plate 17 of the machine from a bobbin and hook mechanism, not shown. The mechanism for operating the needle bar, presser bar, bobbin and bobbin hook are conventional and hence the details thereof will not be described.

In accordance with this invention, the presser b'ar114 is provided with a novel presser foot 18 comprising a horizontally disposed portion 19 and a vertically extending portion 20 which may be an integral ange but is here shown as an angle member welded to the portion 19. The vertical portion 20 of the presser foot is attached to the presser bar 14 by any suitable means so that the presser foot is raised and lowered in the usual manner by actuation of the presser bar. An important feature of this invention is the provision of a groove Z1 on the lower or material-engaging surface of the horizontal portion 19 of the presser foot. This groove extends from front to rear of the lower surface of the presser foot and intermediate its ends is provided with an opening 22 which accommodates the needle 15. The opening 22 is of suicient dimension to permit the needle 15 to be laterally moved and effect a sewing operation at two laterally spaced locations thus producing the aforementioned zigzag type of stitch. i

The base plate 17 of the sewing machine is provided with a novel throat plate 23 which may be mounted upon the base plate in conventional manner. The throat plate is provided with an opening 24 for receiving the needle 15 and this opening is aligned with the opening 22 in the presser foot. In order to insure this alignment, and to maintain the presser foot in proper vertical alignment with the throat plate for the purposes hereinafter described, a guide means is provided therebetween. As here shown, this guide means comprises a post 25 which is secured to the throat plate 2.3 and extends vertically therefrom with a sliding fit through an aligned opening in the horizontal portion 19 of the presser footV 18. The vertical extent of the post 25 is such that the presser foot 18 remains in engagement therewith when raised to its maximum upper position as shown in Fig. 2, thus, guiding the foot and maintaining its predetermined relationship with the throat plate both when work is being positioned and removed and also when the presser foot is moved during the sewing operation.

The groove 21 in the presser foot is of a width such to receive two cords which are to be united or spliced in parallel contiguous relationship and maintain the cords in side-by-side contact. For this purpose the width of the groove is substantially equal to the combined diameters of the cords, two portions of which are indicated in enlarged scale at 26 and 27 in Fig. 5. The depth of the groove 21 is less than the diameter of cords 26 and 2'7 and preferably is in the order of approximately 60% of the diametre of a single cord. This permits the cordsvto extend beneath the presser foot for engagement by the feeding mechanism of the sewing machine and to be moved thereby during the sewing or splicing operation.

The cords to be spliced, such as 26 and 27, are maintained in the groove 21 of the presser foot when the latter is lowered to its sewing position by a member which is positioned to move from beneath the throat plate to a position above the latter and into contact with the cords. In the preferred embodiment, this member, generally designated 28, comprises an upper portion 29 of rectangular cross section which extends through a correspondingly shaped opening in the throat plate 23 in front of and aligned with the needle opening 24. The member 28 is resiliently urged upwardly by a coil spring 30 which surrounds a shank portion 31 of the member 28 and acts between an enlarged shoulder or collar portion 32 on the member and a mounting bracket 33 for the member. In the illustrated embodiment, the bracket 33 is substantially U-shaped with horizontally outwardly extending projections which are removably secured to the bottom of the throat plate 23 by suitable means such as screws 34 and 35. The bight portion of the bracket 33 has an opening for receiving the shank portion 31 of the member 28 with the said shank portion extending therethrough with a sliding tit so that it is guided in its vertical movement. Likewise, the rectangular portion 29 has a sliding tit in the opening provided therefore in the plate 23 so that the member 28 is free to partake of limited vertical movement without appreciable lateral movement or play. The collar 32 on the member 28 acts to limit the upward position of the member 28 as will be apparent from Fig. 2.

The throat plate 23 is provided with an elongated opening 36 to the rear of the needle opening 24 and in alignment with the latter and the opening for the member 28.. A feed dog 37 having a single elongated material-engaging upper surface extends through the opening 36 and is attached to a feed dog bar 38 which is operated by the conventional feed operating mechanism of the sewing machine, which mechanism is not here shown. Preferably, the upper surface of therfeed dog 37 has a iine cross cut pattern therein rather than the coarse teeth usually provided on the conventional feed dog.

The splicing or uniting of two cords in accordance with this invention is effected by raising the presser foot 18 to the upper position as shown in Fig. 2 thus allowing the member 28 to extend to its uppermost position. The needle bar 13 is also raised so that the needle 15 is positioned above the needle opening 22 in the presser foot. The two cords, such as 26 and 27 which are to be spliced, are then held side-by-side and placed in this relationship within the groove 21. While the cords are thus held, the presser foot 18 is lowered. This moves the horizontal portion 19 of the presser foot to its lower position so that the cords 26 and 27 are engaged by the upper surface of the feed dog 37 and by the upper surface of the portion 29 of the member 28, thus firmly retaining the cords within the groove 21. In this position of the mechanism, the member 28 is moved downwardly by compression of the spring 30 but the upper surface of the portion 29 extends above the throat plate 23 to the posit-ion permitted by the presence of the cords 26 and 27 and the presser foot portion 19.

`The sewing machine, having previously been supplied with suitable thread upon both the spool 16 and the bobbin, not shown, is then placed in operation. This cause's the feed dog 37 to move the cords 26 and 27 beneath the presser foot while the cords are maintained within the groove 21 by the member 28. During this movement, the needle alternately engages the cords 26 and 27 uniting them together by a zigzag stitch as indicated in Fig. 5. The length of the resulting region of union or splicing may be of any desired extent commensurate with the strength required in the splice and the use to which the spliced cords will be placed. The splicing operation is terminated by stopping the sewing machine and the cords are removed by raising the presser foot thus freeing them as will be evident from the position of the parts shown in Fig. 2. The resulting splice will have a maximum transverse dimension which is substantially the same as the combined diameters of the cords so that the spliced cord can be readily fed through guiding and tensioning means for incorporation in textile fabrics, reinforcement of elastomeric articles or any purpose in which cords are normally employed.

The member 28 serves to positively maintain the cords within the groove 21 throughout the sewing operation thus insuring that the cords will be accurately positioned for proper contact by the needle 15. Moreover, lateral shifting of the cords is prevented by the fact that the presser foot 18 is positively guided by the post 25 and hence the motions imparted to the presser foot during the sewing operation do not result in any lateral shifting of position of the presser foot nor can the cords to be spliced be freed from the groove 21 since the member 28 remains in positive engagement therewith. The nature of the feed dog also contributes to the accuracy of the operation by virtue of its location and the tine cross cut on its top surface.

The invention has, for simplicity, been described with reference to details of one speciiic embodiment. It will be apparent, however, that the invention is not limited to the exact construction shown and described but that variations may be made. Moreover, the mechanism of this invention is not limited to use in splicing two cords since it may be utilized in uniting two materials having beaded or raised edge portions. Other uses and adaptations of the invention will occur to those skilled in the art to which the invention pertains. Consequently, the invention is not to be considered as limited except as required by the spirit and scope of the appended claims.

Having thus described the invention, I claim:

1. In a sewing machine, a throat plate having a needle opening intermediate its front and back edges, a member supported beneath said throat plate for vertical movement through an opening in said plate in line with and in front of said needle opening, means to move said member upwardly to dispose the upper end of the latter above the upper surface of said plate, a feed dog extending through an opening in said plate to the rear of said needle opening and, a presser foot supported for vertical movement above said plate, the said foot including a generally horizontally disposed portion extending above said feed dog and member and cooperating therewith to engage material placed therebetween with the material engaging lower surface of said presser foot having a groove extending from the front to the rear thereof in alignment with said feed dog and member for receiving a portion of the material to be sewn, and the said presser foot having a needle opening therethrough communicating with said groove.

2. In a sewing machine having needle means actuated to unite material in side-by-side adjacentrelationship, a throat plate having a needle opening intermediate its front and back edges, a member supported beneath said throat plate for vertical movement through an opening in said plate in line with and in front of said needle opening, means to move said member upwardly to dispose the upper end of the latter above the upper surface of said plate, a feed dog extending through an opening in said plate to the rear of and in line with said needle opening, a presser foot supported for vertical movement above said plate, the said foot having an elongated generally horizontally disposed portion extending above said feed dog and member and cooperating therewith to engage material placed therebetween with the material engaging lower surface of said presser foot having a grooverextending from the front to the rear thereof in alignment with said feed dog and member for receiving a portion of the material to be united, the said presser foot having a needle opening therethrough communicating with said groove,

and means for maintaining said presser foot in predetermined vertical alignment with said member and feed dog in all positions of the presser foot.

3. The combination as defined in claim 2 wherein the means to move said member upwardly is a spring. Y

4. In a sewing machine adapted to perform a stitching operation alternately at two laterally-spaced locations, a throat plate having a needle opening intermediate its front and back edges, a member supported beneath said throat plate for vertical movement through an opening in said plate in line with and in front 'of said needle opening, means resiliently urging said member upwardly to dispose the upper end of the latter above the upper surface of 9. In a sewing machine having needle means actuated to unite material in side-by-side adjacent relationship, a throat plate having a needle opening intermediate its front and back edges, a member supported beneath said throat plate for vertical movement through an opening in said plate in line with and in front of said needle opening, means to move said member upwardly to dispose the upper end of the latter above the upper surface of said plate, means to limit the extent of upward movesaid plate, a feed dog extending through an opening in said plate to the rear of and in line with said needle opening, a presser foot supported for vertical movement above said plate, the said foot having an elongated generally horizontally disposed portion extending above said feed dog and member and cooperating therewith to engage material placed therebetween with the lower material engaging surface of said presser foot having a groove extending from the front to the rear thereof in alignment with said feed dog and member for receiving a portion of the material to be stitched, the said presser foot having a needle opening therethrough communicating with said groove, and vertical guide means for maintaining said presser foot in predetermined vertical alignment with said member and feed dog in all positions of the presser foot.

5. The combination as defined in claim 4 wherein said guide means comprises a rigid member extending between said throat plate and presser foot and secured to one of the latter with a sliding t in an opening of the other.

6. The combination as delined in claim 4 wherein said vertical guide means is a post secured to said throat plate and extending with a sliding fit through an opening in said presser foot. i

7. A sewing machine for uniting two cords in side-by-A side relationship by a stitching operation comprising needle means actuated Vto alternately engage the cords, a throat plate having a needle opening intermediate its front and back edges, a member supported beneath said throat plate for vertical movement Vthrough an opening in said plate inline with and in front of said needle opening, means to move said member upwardly to dispose the upper end of the latter above the upper surface of said plate, a single feed dog extending through an opening in said plate to the rear of and in line with said needle opening, a presser foot supported for vertical movementaboveY said plate, the said foot having an elongated generally horizontally disposed portion extendingV abovesaidfeed` dog and member and cooperating therewith to engage the cords placed therebetweenwith the cord-engaging lower surface of said presser foot having a groove extending from the front to the rear thereof in alignment with said feed dog and member for receiving the cords to be united, the said presser foot having a needle opening therethrough communicating with said groove, and means for maintaining said presser foot in predetermined vertical alignment with said member and feed dog in all positions of the presser foot.

8. A sewing machine as defined in claim 7 wherein the width of the groove in such presser foot is approximately equal to the combined diameters of the cords to be united and the depth of said groove is less than the diameter of said cords.

ment of said member, a feed dog extending through an opening in said plate to the rear of and in line with said needle opening, a presser foot supported for vertical movement above said plate, the said foot having an elongated generally horizontally disposed portion extending above said feed dog and member and cooperating therewith to engage material placed therebetween with the material-engaging lower surface of said presser foot having a groove extending from the front to the rear thereof in alignment with said feed dog and member for receiving a portion of the material to be united, the said presser foot having a needle opening therethrough communicating with said groove, and means for maintaining said presser foot in predetermined Vertical alignment with said member and feed dog in all positions of the presser foot.

10. In a sewing machine having needle means actuated to unite material in side-by-side adjacent relationship, a throat plate having a needle opening intermediate its front and back edges, a member supported beneath said throat plate for vertical `movement through an opening in said plate in line with and in front of said needle opening, a spring acting on said member to move it upwardly to dispose the upper end thereof above the upper surface of said plate, means on said member to limit the extent of its upward movement, a feed dog extending through an opening in said plate to the rear of and in line with said needle opening, a presserfoot supported for vertical movement above said plate, the said foot having an elongated generally horizontally disposed portion extending above said feed dog and member and cooperating therewith to engage material Vplaced therebetween with the material-engaging lower'surface of said presser foot having a groove extending from the front to the rear thereof in alignment with said feed dog and member for receiving a portion of the material to be united, the said presser foot having a needle opening therethrough communicating with said groove,'and means for maintaining said presser foot in predetermined vertical -alignment with said member and feed dog in all positions of the presser foot, the last-named means comprising a rigid member extending between said throat plate and presser foot and secured to one of the latter with a sliding tit in an opening of the other.

References Cited in the file of this vpatent UNITED STATES PATENTS 639,726 Grieb Dec. 26, 1899 735,477 Douglas Aug. 4, 1903 1,526,937 Sharaf Feb. 17, 1925 1,864,370 Picard June 21, 1932 2,207,977 Firm July 16, 1940 2,374,529 Everitt Apr. 24, 1945 2,380,912 Walter July 31, 1945 2,435,457 McLendon Feb. `3, 1948 2,500,731 Zeier Mar. 14, 1950 

